From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian King Subject: scsi_tcq.h questions Date: Mon, 02 Aug 2004 16:11:03 -0500 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <410EADE7.3050307@us.ibm.com> Reply-To: brking@us.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from e1.ny.us.ibm.com ([32.97.182.101]:17568 "EHLO e1.ny.us.ibm.com") by vger.kernel.org with ESMTP id S263709AbUHBVLF (ORCPT ); Mon, 2 Aug 2004 17:11:05 -0400 Received: from northrelay04.pok.ibm.com (northrelay04.pok.ibm.com [9.56.224.206]) by e1.ny.us.ibm.com (8.12.10/NS PXFA) with ESMTP id i72LB5OZ220444 for ; Mon, 2 Aug 2004 17:11:05 -0400 Received: from us.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by northrelay04.pok.ibm.com (8.12.10/NCO/VER6.6) with ESMTP id i72LC6DK070192 for ; Mon, 2 Aug 2004 17:12:06 -0400 List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org I have a question related to the utility functions found in scsi_tcq.h. The comment above scsi_activate_tcq indicates that the depth passed in should be the maximum depth the device can cope with and the real queue depth would be adjustable. This seems to contradict what is done in 53c700.c, as queue depth is a sysfs file which is defaulted to 4 and can be raised to 16. Since scsi_adjust_queue_depth never calls blk_queue_resize_tags, we end up with a larger queue depth in scsi than the block layer is aware of. So, which is correct? Should scsi_adjust_queue_depth be changed to call blk_queue_resize_tags and the comment be removed from scsi_activate_tcq, or should the call to scsi_adjust_queue_depth in scsi_activate_tcq be removed and the queue depth passed in scsi_activate_tcq be a true max queue depth, in which case 53c700 should be changed to reflect this? -- Brian King eServer Storage I/O IBM Linux Technology Center